Optical instrument.



Fig.1.

WTA/ESSES' B. F. MAYO. OPTICAL INSTRUMENT.

. w ur'uoumq rum) MAR. 9, 1910. 7 v Patented 001;. 18,1910.

3 BHEETB-8HEET 1.

B. F. MAYO. OPTICAL INSTRUMENT. nrmornox nun 1mm, 1910.

Patented Oct. 18,-1910.

I a sums-sum 2.

Fb z.54499975744145! 4 Fig. 5

VWTA/LSSES'.

Me. 5 C

B. F. MAYO.

OPTICAL INSTRUMENT. A'rrmoxnon rmm MAB. a, 1910.

3 SHEETS-SHEET 3.

973,062. Patented Oct. 18,1910.

' I as 63 g 38 66 Fig. 6.

WT/VESSES. Wl/E/VTJR- BENJAMIN F. MAYO, OF SALEM, MASSACHUSETTS.

or'r'ioAL INSTRUMENT.

Specification of Letters Patent. Patented Oct. 18, 1910.

Application filed March 9, 1910. Serial No. 548,168.

Toall whom it may concern:

Be it known that I, BENJAMIN F. MAYO,

a citizen of the United States, residing at Salem, in the county ofEssex and State of Massachusetts, have invented certain Improvements inOptical Instruments, of which the following description, in connectionwith the accompanying drawings, is a specification, like referencecharacters on the drawings indicating like parts in the several figures.

This invention relates to astronomical and surveying instruments.

.I-Ieretofore' it has been customary to use the well-known plumb lineand bob in work which required plumbing or truing a line or point. Theordinary plumb line and bob are objectionable however, because ofinaccurac and unsteadiness, and 1 because the plumb line must besupportedj;\ from above the work, and also for the further reason thatit cannot be used where work upon an angle or slope is involved, withoutgreat care, the taking ofmany measurements and loss of time.

An object of this invention is to provide a plumbing instrument whichmay be utilized in place of a plumb line and bob and which will beaccurate and reliable in use.

To this end, an object of the invention is to providea device which maybe held at a height, as in the case of a plumb line, to enable theoperator to sight downwardly, or which may be used to sight upwardly,and which is also capable'of plumbing at any desired angle with thevertical.

It is a further object of the invention to provide means to shield orguard a plumbing device from the deflecting influences of air currents.It will be readily appreciated that air currents, however slight, affectthe accuracy of use of a plumb line, while of course a plumb line isrendered useless in a breeze.

An additional object of the invention is to provide an instrument foruse in aviation to enable an aviator to locate accurately his positionwith relation to the surface of the I earth. An observer in an aerialcraft, when face, cannot determine with accuracy what but a shortdistance above theearths sur- 1 portion of the surface he is verticallyover,

and 'when ata considerable height points or places on the surface whichare in fact several miles apart will each appear to be as directly underthe observer as any other. By means of the mariners compass, such anobserver can readily orient his position with respect to the horizontalplane, and this invention provides an instrument which will enable theobserver to ascertain similarly his position with res ect to thevertical plane' So far as app icant is aware, this feature of theinvention is a distinct novelty in the art'and it is desired to claimthe same broadly.

Other objects of the invention are to-provide an instrument to enable anaviator to determine his height above the earth and the speed of hismovement over it, to locate with precisionthe point upon the earthssurface upon which an article will land when dropped from an aerialcraft either while in motion or at rest, ard accordingly to providemeans to compensate for speed, or' for drift caused by'an air current,or both; also to furnish a finder to enable an aviator to determine thedirection of his line of flight with respect to the surface of the earthover which he'may be passing.

The invention contemplates the employment of any suitable device as thesighting means, which means is sustained normally plumb from anappropriate support. Preferably such sightingnneans consists of atelescope of satisfactory size and power for the purpose for which thedevice is to be used, but itiswithin the scope of the invention toemploy any suitable sighting means, such as .a hollow tube, or a rod, ora plurality of sighting points similar to those used in the art ofgunnery, which means are normally sustained in a plumb position. In casea telescope or similar device is employed, it is preferable to equipsuch device with a reticule or cross hairs to more accurately determinethe center of the field of view.

' In the preferred embodiment of the invention as herein shown, atelescope is utilized as the sighting means through which the observerlooks to true up or plumb the desired line or oint. The telescope ispreferably mounte to hang from its uppermost portion, as by means ofgimbals or a universal joint, and is arranged to swing freely in anydirection. Thus the telescope itself the angle at which t e supportingmeans may be held. In order to obviate the action I of air .currents andwinds whichmlght dc-' flectthe telescope from its normally plumbposition, a circular ard or shield p artially surrounding the te escopemay be conveniently attached to the supporting means from which thetelesco e is hung. The supporting means, inclu ing the wind guard may beprovidedwith handles to be gras d by the observer as he sights downwarly, and it may also be arranged to stand upon a bench or upon the groundfor sighting upwardly. I

When the device is used for sighting upwardly it is preferable to have ahorizontal e-piece, and a horizontal eye-piece may e a so be mountedupon the instrument when intended to be used for sighting downwardly.

In order to incline the telescope at any desired angle out of plumb, as,for example, in sighting along the slope of a church steeple or for usein aviation asabove mentioned, means is provided to adjust the barrelofthe telescope into and out of plumb with great exactness and inaccordance with -a scale. Said means comprises an additional plumbingdevice, preferably a weight heavier than the telescope, which weight isalso hung from gimbals and arranged in immediate proximity to thetelescope with an adjustable connection between the weight and thetelescope. Preferably this weight is in the form of an annulus, arran edto be swung from the upper portion of t e telescope just below thesupporting gimbals and with the barrel of the telescope passing throughits center. A suflicient space is provided between the inner diameter ofthe annulus and the outer diameter of the barrel to permit an adjustableconnection which will preferably comprise means whereby the barrel ofthe telescope may be quickly ositioned and held at any desired angle reatively to the annulus, the latter being of suflicient weight to insurethat it will still hang substantially plumb irrespective of the slightlateral ressure ut upon it by the deflection o the barre of t etelescope through the action of the adjusting means in moving and hold,-

ing said barrel out of plumb. Of course any movement of the telescopeout of plumb through lateral pressure upon the weight tends to deflectsaid wei ht proportionally in the opposite direction om that in whichthe telescope is swung? However, the scale which is used to indicate theangle of the telescope in .its various adjustments is so constructed asto equate the deflection of the annulus by the telesco e and indicatecorrectly the obliquity of e line of sight.

Other im ortant features, combinations of parts, an details ofconstruction will be bal ring 15, being hereinafter more particularlydescribed and claimed.

Referring to the drawings, illustratin a preferred embodiment of theinvention, 1gure 1 is a general view of my complete device, with aportion of the wind shield broken away; Fig. 2 is a view in perspectiveupon an enlar ed scale, with a small portion of the wind s 'eld in crosssection; Fig. 3 is a longitudinal sectional view of the device; Fig. 4is a detailed view of the means of adjustment between the wei ht and thetelescope; Fig. 5 is a View, in ongitudinal section, of the device witha horizontal eyepiece for sighting downwardly; and Fig. 6 IS a view,also in ongitudinal section, of the device arranged for sighting uwardly.

In the drawings, the numera 1 designates that portion of a terrestrialtelescope containing the eye-piece, and 2 designates the objective, end,the portions 1 and 2 being arranged to sl1de relatively with each otherupon the bearings of the member 3 inv the usual manner. The cross-hairsare indicated by 4.- at a diaphragm of the eye-piece. The telescope isarranged to be sustained at its upper end by a universal jointconnection. As herein shown this connection is by means of gimbals,comprising a collar 5 upon the eye-piece in Figs. 1, 2, 3 and 5, or uponthe barrel 2 as shown in Fig. 6, adjustable pins 7 and 8 threadedthrough an intermediate rin 10 and bearing in suitable recesses in theco lar5, and an outer ring 15 having pins 12 and 13 similarly bearingrinrecesses in the intermediate ring 10. he pins 7 and 8 are diametricallyopposed and the pins 12 and 13 are also diametrically opposed and on adiameter at right angles to the former, the four pins being in the sameplane as is-.- customary. If desired, friction washers 9 and 14: may beused as shown in Fig. 2- to prevent too free a movement of the gimbals.By this construction the telescope is sustained normally lumb. Twohandles 17 and 18 areprovid forthe convenience of the observer and suchhandles are secured by any appropriate means to the outer impreferablyattache to said ring in substantially the same plane in which the pins12 and 13 lie. A wind shield 20 is also attached to the ring 15 by anysuitable connection, such as stra s 19, and is preferably in the form ofa ho low truncated cone with the flarin end or base positioneddownwardly. Sai shield may be of any length suflicient to pro erlyrotect the device sustained within it rom t e deflecting influences ofair currents and is herein shown as of slightl greater len h than theportion 2 of the to escope. Suc 'a shield is adaptable to similarlprotect a plumb line and bob or any like p umbing device.

. Means to adjust the portions 1 and 2 of the telescope relatively witheach ther is proiao the arrangement shown in Fig. 6, an aperture 32 isprovided in the wind shield 20' for the horizontal eye-piece to.projectthrough in case it ispreferred to have said shield extend belowthe eye-piece. In this construction also three or more adjusting screws33 are provided to position the 'device firmly on the ground, stand, orother support, when usedfor sighting upwardly. An adjustable point 36 isprovided as also shown in Fig. 6 to aid the observer in accuratelypositioningthe device over a station point, and a window 37] in theshield 20 affords a convenient means for observing when said point isimposition.

As thus far described, the sighting means is'sustained normally plumb,and to position and to hold said means out of plumb addi-- tional means,also normally sustained plumb, is provided with a connection between thesighting means and such additional means.

This means is preferably'a weight 40'arranged in the form of an annulusto encircle the lower portion of the telescope and supported by rods 42,42 attached toia collar 41' secured to the upper part of the telescopejust below the collar' 5. If desirable, sald weight may be supportedfrom the collar 5 or otherwise from the gimbals. The inner diameter ofthe annulus 40 is sufliciently larger than the exterior diameter of thetelescope to leave ample space for the adjustments about to bedescribed.

in Fig. 4 is shown in detail an adjustable connection between the Weight40 and the lower portion of the telescope comprising a threaded rod 43pivotally attached to the barrel of the te escope and extending througha lug 44 on the weight'40. A thumb nut 45 is threaded onsaid rod 43- andbears against the lug 44. Manipulation of the thumb nut 45 serves tomove the barrel of the telescope relatively to the weight 40, and

to holdit in theposition to which it is moved- A pointer 47 aflixed tothe side of the telescope and a suitable scale 48 on tl 1e weight areprovided to indicate the-angle or amount of relative movement of theweight and the telescope. As this movement just described is upon onediametrical line, the annulus 40 is preferably formed with the interioropening of greater diameter in the direction of such movement only, asillustrated in Fig. 4.

Preferably the weight of the annulus 40 is so much greater than that ofthe telescope that the annulus will hang substantially plumb whenthetelescope is out of plumb. However, the weight of the telescope when inan oblique position tends to deflect slightly the annulus 40 in theopposite direction i from that in which the telescope is inclined.

Therefore, the scale 48 is so proportioned that these opposite movementsof the annulus and telescope are equated and the scale will alwaysindicate the exact angle of the line of sight of the telescope with thetrue vertical.

In operating the device the observernf at a height grasps the handlesand sights downwardly, adjusting the telescope to proper focus, and asthe telescope itselfis sustained normally plumb, the observer'obtains anexact vertical sight. By means of the adjustable connection between theweight and the telescope, the latter may be positioned to a desired lineof sight at an angle to the vertical.

- In operating the device for sighting upwardly the observer may eithergrasp the handles and hold it, or may position it upon the ground; astand, bench, or the like.

In using the device of the invention in aviation, an observer can at anytime determine what point on the earths surface he is exactly over bysimply sighting downwardly through the telescope when it is plumb. Thespeed is easily reckoned by noting the time when the observer isvertically over one point, and again when verticallyover a second pointon the surface, the distance between the two points being known. Theheight may be obtained with equal accuracy by noting the angle at thepoint of observation between the vertical and the line of sight to apoint on the earths surface at one side, if the distance on the surfacebetween such point and the point vertically beneath the observer isknown, since from two angles and the length of one side of a trian lethe lengths of the other sides may vreadi y be determined.

To locate on the earths surface the spot where an article dropped froman aerial craft will land, if the observer knows the speed of such craftacross and the height above the surface he can adjust the telescope atthe proper angle to compensate for such speed and height and thusdetermine with precision the point on the surface where said articlewill land. If it was desired that the article should land at' aparticular point on the earths surface the observer can adjust or Setthe instrument at the proper angle to compensate for speed and heightand observe when thedesired I point came into his range of vision andthen aviator can determine the direction of the line of flightrelatively to the earths surface by noting the direction objects on thesurface would seem to take in passing across the field of vision of theshield. As such shield is of flaring form with a large objective fieldof view the observer can readily see whether his line offlight wouldtake him. directly over a certain point on the earths surface and, ifnot, he can perceive what direction must be taken by the aerial craft inorder to place it over or nearly over such point. Y

Another instance of the utility of the de- .'vice of this invention isthat it may be substituted for a plumb line and bob in a surveyorstransit and the transit can then be located over a, station point-ofdeparture much more quickly and accurately than with the use of theplumb line and bob.

Having described my invention, what I claim as new and desire to secureby Letters Patent of the United States is 1. In a device of the classdescribed, sighting means and supporting means therefor arranged tosustain said sighting means normally plumb.

2. In a device of-the class'described, means for sighting downwardlyfrom the point of observation, and supporting means arranged to sustainsaid means normally plumb.

3-. In a device of the class described, sight-.

ing means sustained normally plumb, and means to move said sightingmeans out of plumb.

a 4. In a device of the class described, sighting means sustainednormally plumb and means to hold said sighting means out of plumb. j

' 5. In a device of the class described, sighting means sustainednormally .plumb and means for adjusting said sighting means intoa'position at a desired angle with the vertical.

' 6. In a device of the class described, sighting means, a supporttherefor arranged to sustain said means normally plumb and means tolocate the center of the field of 5 view of said sighting means.

A device of the class described, com- -:-'-"prising a telescope, andsupporting means I thereforarr'anged: to hold the telescope norlypl-umb.

,device of the class described, com-- prising a telescope, supportingmeans therefor arranged to hold the telescope normally plumb, and meansto move said telescope out of plumb.

9. A device of the class described, comprising a telescope, supportingmeans therefor arranged to hold the telescope normally plumb, and meansto move said telesco out of plumb and to hold it in the position towhich it is so moved.

10. A device of the class described, comprising a telescope, supportingmeans therefor arranged to hold the telescope normally plumb, and meansto locate the center of the field of view.

11. A device of the class described, comprising a telescope, supportingmeans therefor arranged to hold the telescope normally plumb, and ashield for preventing deflection of the telescope from normal position.

12. A device of the class described, comprising a telescope, supportingmeans therefor arranged to hold the telescope normally plumb, and meansto prevent. deflection of the telescope from normal position by theaction of air currents.

13. A device of the class described, comrising a telescope, supportingmeans therefor arranged to hold the telescope plumb, and a wind shieldconnected to said support. 14. A device of the class described,comprising a telesco e, supporting means therefor arranged to old thetelescope normally plumb, and a wind shield surrounding the telesco e.

15. device of the class described, comrising a telescope, supportingmeans thereor arranged to hold the telesco e plumb,

and a wind shield having the orm of a hollow truncated cone partiallyinclosing said telescope and connected to said support.

16. A device of the class described, comprising a telescope, supportingmeans therefor arranged to hold the telescope plumb, and a wind shieldsurrounding the telescope, said parts bein constructed to ermit sightthrough the shield between tie telescope and the shield.

17. A device of the class described, comprising a telescope, supportingmeans there for arranged to hold the telesco e plumb, and a circularflaring wind shiel attached to said support and surrounding thetelescope, said arts being constructed to permit sight trough the shieldbetween the telescope and shield.

18. A device of the class described, comprising a telesco e, supportingmeans therefor a universe oint connection between said support and theupper ortion of said telescope, and a wind shiel connected to thesupport, said shield being in the form of a hol ow truncated cone andarranged to partially surround the telescope, the universal jointconnection being constructed to range tional meanssustained normallyplumb from permit s between the telescope andthe ieldi- 19. A device ofthe classzdescribed, coinprising a telescope, su' porting means thereforarranged to hold t is telescope normally plumb, and means, foradju'sting'said telescope into a positionipu-tofplumla v I 20. A devlceofthe' classjdescribed, com.-

prising a telescope; supporting f'me'ans there-,-

or arranged to' hdld- -the teles'co' .plu'mb,

additional means sustainedfby sai support- 1ng means and 'a connect1onbetween said telescope and said means whereby the telescope may be movedto and. held in a position out of plumb..

21. A device of the class described, comprising a telescope, a supporttherefor arranged to hold the telescope plumb, additional meanssustained normally plumb from said support, and an adjustable connectionbetween said telescope and said means whereby the telescope maybe movedtoa position out of 1plumb while said means remains substantia 1y plumb.I

22. A device of the class desc'ribed,.comprisin a telescope, asupport''thereforsar- 5 to hold the telescope plumb, addisaidsupport,and. means to adjust the. telescope to 'an oblique position, while said'additional means is maintained ;.in. su'bstantially plumb position.

23. A device of theclass described, .including a'telescope, a supporttherefor arranged to hold the teles'copeplumli, means heavier than thetelescope sustained normally plumb from said support, and an adjustableconnectionbetween said means and- I I the telescope to move thetelescope to a position at an angle to the vertical.

24. In an apparatus of the class described, a support, a sighting devicearranged to hang normally plumb from said support,

and means to prevent deflection of said device from normal position byair currents. L, 25.-In a device of the class described, a telescopesupported at its uppermost por- "tion by gimbals and means to steady thegimbals.

26. In a device of the class described, a telesco e supported at itsuppermost portion by gim als and a handle secured to said gim bals insubstantially the same v plane with the pivot pins of said gimbals.

27. In a device of the class described, a telescope supported atzitsuppermost port-ion by gimbals, washerson the gimbal pins, a handlesecured to said gimbals in substantially 'the same plane with the pivotpins and a wind shield supported by said handle.

28. In a device of the class described,a telescope supported at itsuppermost por' tion by gimbals, a weight heavier than said telescopesustained normally plumb by said gimbals, and an adjustable connectionbotween the weight and the telescope whereby the line of sight of thetelescope may be moved to a position at a desired angle with the,Vertical.

In testimony whereof I have signed my name to this specification in thepresence of twosubscribing witnesses. I

' BENJAMIN F. MAYO. Witnesses: JAMES.R. Hononn,

FREDERICK L. EDMONDS.

